<template>
  <div id="home">
    <nav-bar class="home-nav"><div slot="center">购物街</div></nav-bar>
    <tab-control
      class="tab-control"
      ref="tabControl1"
      :titles="['流行', '新款', '精选']"
      @tabClick="tabClick"
      v-show="isTabFixed"
    ></tab-control>
    <scroll
      class="content"
      ref="scroll"
      :probe-type="3"
      @scroll="contentScroll"
      :pull-up-load="true"
      @pullingUp="loadMore"
    >
      <home-swiper
        :banners="banners"
        @swiperImageLoad="swiperImageLoad"
      ></home-swiper>
      <recommend-view :recommends="recommends"></recommend-view>
      <feature-view></feature-view>
      <tab-control
        ref="tabControl2"
        :titles="['流行', '新款', '精选']"
        @tabClick="tabClick"
      ></tab-control>
      <goods-list :goods="showGoods"></goods-list>
    </scroll>
    <back-top @click.native="backClick" v-show="isShowBackTop"></back-top>
  </div>
</template>

<script>
import HomeSwiper from "./childComps/HomeSwiper.vue";
import RecommendView from "./childComps/RecommendView.vue";
import FeatureView from "./childComps/FeatureView.vue";

import NavBar from "components/common/navbar/NavBar.vue";
import TabControl from "components/content/tabControl/TabControl.vue";
import GoodsList from "components/content/goods/GoodsList.vue";
import Scroll from "components/common/scroll/Scroll.vue";

import { getHomeMultidata, getHomeGoods } from "network/home";
import { debouce } from "common/utils.js";
import { itemListenerMixin, backTopMixin } from "common/mixin.js";

export default {
  name: "Home",
  components: {
    HomeSwiper,
    RecommendView,
    FeatureView,
    NavBar,
    TabControl,
    GoodsList,
    Scroll,
  },
  mixins: [itemListenerMixin, backTopMixin],
  data() {
    return {
      banners: [],
      recommends: [],
      goods: {
        pop: { page: 0, list: [] },
        new: { page: 0, list: [] },
        sell: { page: 0, list: [] },
      },
      currentType: "pop",

      tabOffsetTop: 0,
      // 默认不吸顶
      isTabFixed: false,
      saveY: 0,
    };
  },
  computed: {
    showGoods() {
      return this.goods[this.currentType].list;
    },
  },

  // 进入页面时调用
  activated() {
    this.$refs.scroll.scroll.scrollTo(0, this.saveY, 1);
    // 针对返回后不能滚动的问题
    this.$refs.scroll.scroll.refresh();
  },

  // 离开页面时调用
  deactivated() {
    // 1、保存Y值
    this.saveY = this.$refs.scroll.getScrollY();

    // 2、取消全局事件的监听
    // this.$bus.$off('itemImageLoad',函数)
    this.$bus.$off("itemImageLoad", this.itemImageListener);
  },
  created() {
    // 1、请求多个数据
    this.getHomeMultidata();
    // 2、请求商品数据
    this.getHomeGoods("pop");
    this.getHomeGoods("new");
    this.getHomeGoods("sell");
  },

  mounted() {
    // 图片加载完成的事件监听
    // 调用频繁就先做一层封装
    // let newRefresh = debouce(this.$refs.scroll.refresh, 200);
    // 3、监听item中图片加载完成
    // 对监听的事件进行保存
    // this.itemImagListener = () => {
    // 刷新
    // newRefresh();
    // };
    // this.$bus.$on("itemImageLoad", this.itemImageListener);
    // this.$bus.$on("itemImageLoad", () => {
    //   refresh();
    // });
  },

  methods: {
    // 事件监听相关的方法

    tabClick(index) {
      switch (index) {
        case 0:
          this.currentType = "pop";
          break;
        case 1:
          this.currentType = "new";
          break;
        case 2:
          this.currentType = "sell";
          break;
        default:
          break;
      }
      this.$refs.tabControl1.currentIndex = index;
      this.$refs.tabControl2.currentIndex = index;
    },

    contentScroll(position) {
      // 1、判断BackTop是否显示
      this.isShowBackTop = -position.y > 1000;

      // 2、决定tabControl是否吸顶(position:fixed)
      this.isTabFixed = -position.y > this.tabOffSetTop;
    },

    loadMore() {
      // 加载当前选中页面的更多
      this.getHomeGoods(this.currentType);
    },

    swiperImageLoad() {
      // 2、获取tabControl的offsetTop
      this.tabOffSetTop = this.$refs.tabControl2.$el.offsetTop;
    },

    // 网络请求相关方法

    getHomeMultidata() {
      getHomeMultidata().then((res) => {
        this.banners = res.data.banner.list;
        this.recommends = res.data.recommend.list;
      });
    },

    getHomeGoods(type) {
      const page = this.goods[type].page + 1;
      getHomeGoods(type, page).then((res) => {
        this.goods[type].list.push(...res.data.list);
        // 多了一组数据后，页码要加一
        this.goods[type].page += 1;

        // 完成上拉加载更多
        this.$refs.scroll.finishPullUp();
      });
    },
  },
};
</script>

<style scoped>
#home {
  /* padding-top: 44px; */
  /* 100%个视口 */
  height: 100vh;
  position: relative;
}
.home-nav {
  background-color: var(--color-tint);
  color: #fff;

  /* position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 9; */
}
.tab-control {
  position: relative;
  /* top: 44px; */
  z-index: 9;
}
.content {
  /* height: calc(100%-93px); */
  overflow: hidden;

  position: absolute;
  top: 44px;
  bottom: 49px;
  left: 0;
  right: 0;
}
</style>